Recently, an audio video navigation (AVN) terminal or a head unit has been mounted in a vehicle. The AVN terminal may provide not only a navigation function for providing a route to a destination to a user but also a display function of various control screens related to control of various devices installed in the vehicle or a display function of screens related to additional functions capable of being executed in the AVN terminal.
Therefore, studies on technology for controlling devices in the vehicle by the user by manipulating the AVN terminal through a display implemented as a touchscreen or through a jog shuttle type controller have been actively conducted.
Recently, rapid development of information technology (IT) has a significant effect on the automobile industry and various IT techniques are being incorporated into the vehicle.
In particular, vehicle pairing technology for providing a variety of services by connecting a user device such as a smartphone to a vehicle AVN terminal is in the spotlight.
For example, the vehicle may be equipped with a Bluetooth hands-free function. The Bluetooth hands-free function may be provided by a Bluetooth module included in the AVN terminal.
Generally, when the vehicle starts, a Bluetooth function of the AVN terminal is automatically activated so that the AVN terminal enters a pairing standby state. Then, the driver of the vehicle performs a Bluetooth pairing procedure by selecting a predetermined menu through the smartphone. If the pairing procedure is normally completed, the driver may make a phone call through the Bluetooth hands-free function.
A Bluetooth function is one of functions that users react most sensitively to among numerous functions provided by the vehicle and corresponds to an item that most frequently causes users to complain.
Accordingly, Bluetooth quality significantly affects a score of an initial quality study.
Currently, up to two Bluetooth devices are connectable to the AVN terminal due to properties of a Bluetooth software driver. Therefore, there is no method of seamlessly connecting three or more Bluetooth devices.